This invention relates to powering of portable electronic devices.
Portable electronic devices are normally powered with either a primary or a rechargeable battery. Growth in the portable electronic device market, as well as, changes in usage patterns, has provided opportunities for rechargeable sources of power to power an electronic device. While primary batteries have a greater energy density, their internal resistance is larger, and primary batteries are less suitable in high drain (>0.2C rate of discharge) electronic devices. Rechargeable batteries can handle large loads but do not have sufficient energy capacity for many applications.
Fuel cells incorporated into power sources for portable devices promise longer runtimes than conventional battery systems, due to the ability to use high-energy content fuels. Several fuel cell technologies are currently under development for commercialization in portable power applications, namely direct methanol fuel cells (DMFC) and hydrogen PEM fuel cells (H2FC). Both require the ability to replenish fuel into the power source when it is used up.